Abstract:Substantial effort has been placed on the implement of semiconductor nanostructures as building blocks for photovoltaic devices, such as dye-sensitized solar cells, all-inorganic solar cells, and hybrid nanocrystal-polymer composite solar cells. All of which could offer alternative advantages when compared with conventional single crystal and thin film solar cells. In many cases, the semiconductor nanostructures that have been employed for solar cells possess a relatively large bandgap ( 1.7eV), leaving a considerable portion of the incident solar energy spectrum unused. To generate photocurrent from low energy photons, low bandgap semiconductor nanostructures are highly desirable. Here we report a solution-phase synthesis approach for monodispersed hexagonal copper (I) sulfide (Cu2S) nanocrystals with a bandgap of 1.26 eV. In addition, we also demonstrate the fabrication of solar cell using the Cu2S nanocrystals and cadmium sulfide (CdS) nanorods on both glass and plastic substrates with the power conversion efficiency of the device exceeding 1.6%.